Cryopreservation and cryoprotectors in protection of the swine sperm
Keywords:
Boar, cyclodextrin, freezing, cryoprotectantsAbstract
The use of frozen semen presents lower conception rates and fewer piglets born per birth. This is due to the fact that cryopreservation causes variations in temperature, changes in sperm permeability and oxidative processes, and the swine semen naturally presents low antioxidant capacity and undergoes oxidative stress. However, several cryoprotectants are used for several species, and the use of cyclodextrin and amino acid-loaded cholesterol is already described, aiming to improve the semen after thawing. The addition of cholesterol to the semen prior to cryopreservation maintains the integrity of the acrosomal membrane and slows sperm capacitation, which can be facilitated by cyclodextrin loading. In parallel, research indicates the importance of the use of amino acids in the semen, which form a layer of thermal protection that preserves the integrity of the sperm cell, in addition to presenting osmorregulatory function. In this sense, the viability of the cryopreservation of the swine semen favors the genetic improvement, minimizes the transmission of pathogens and allows the formation of a germplasm bank. Therefore, it is necessary to improve the use of cryoprotectants in an ideal proportion, which maintains the integrity of the sperm membrane and does not detract from the sperm capacitation and acrosomal reaction required for fertilization.
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